Brush over your newly installed travertine with a dry paintbrush to take off all dust and debris, from the tile surface as well as from the gaps between the tiles.
Use the paintbrush to apply penetrating tile sealant to the surface with a paintbrush. Apply it in a thin, smooth coat. Don't brush into the holes that are on the face of the tiles or in the gaps between them. Let the sealant dry for four to six hours.
Spread unsanded grout over the tile using your grout squeegee to scrape it over the surface and force it into the spaces and holes. Make sure the grout is flat over the holes and spaces.
Let the grout sit in the holes and spaces for about 10 minutes. Wipe down the surface of the tile with a damp sponge, running it flat over the surface to avoid pulling the grout out of the holes and spaces.
Allow the grout to set for five to seven days. Apply two more layers of tile sealant, brushing it over both the tile and grout.